Context:
Under the new terminology by the World Health Organization(WHO), airborne viruses will be called “pathogens that transmit through the air”.
More on News:
- Terminology by WHO-led Working Group: After two years of consultations involving over 100 scientists, a WHO-led working group agreed to the term to describe diseases caused by infectious particles that typically multiply in the respiratory tract.
- These spread from the nose and throat of an infected person while they breathe, speak, sing, cough or sneeze.
World Health Organisation (WHO):
- Established: WHO was founded on 7 April 1948, now celebrated as World Health Day.
- Members: Working with 194 Member States across 6 regions.
- Governing body: The World Health Assembly which is attended by delegations from all Member States.
- UN status: United Nations agency dedicated to advancing health for all.
- Mission: To connect nations, partners and people to promote health, keep the world safe and serve the vulnerable so that everyone, everywhere, can attain the highest level of health.
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- Recognition of Dynamic Spectrum: The WHO’s new terminology acknowledges that infectious respiratory particles exist on a spectrum of sizes.
- It recommends against applying definitive cut off points to distinguish smaller from larger particles.
- This aims to resolve a scientific divide that impeded the initial response to Covid-19.
- Criticism of Decision: Prominent scientists have criticized the reluctance to use the term “airborne.”
- In early 2020, an international group of 36 scientists warned about airborne spread and called on the WHO to change its guidance on Covid-19 transmission.
About Airborne Viruses and Disease:
- About: Airborne viruses like common cold virus (rhinoviruses), measles virus, and influenza virus.
- They enter the body through small droplets (aerosols) and the virus attaches to and penetrates the cells lining the surface of the respiratory tract.
- Replication on Respiratory Tract Cells: These viruses often replicate in the cells of the respiratory tract and cause these cells to initiate a local inflammatory response that results in many of the symptoms of these viral diseases.
- Transmission: Viruses present in the respiratory secretions can be subsequently transmitted by coughing, sneezing, and other similar modes of spread to other susceptible individuals.
Examples of Airborne Diseases:
- Common cold, which can develop from a rhinovirus
- Chickenpox, caused by the Varicella zoster virus
- Mumps and Measles caused by a paramyxovirus
- Whooping cough, a bacterial infection caused by Bordetella pertussis
- COVID-19, caused by the SARS-CoV-2 virus
- Aspergillosis, caused by the Aspergillus fungus
- Anthrax, a bacterial infection resulting from contact with Bacillus anthracis spores
- Diphtheria, a bacterial infection caused by Corynebacterium diphtheriae
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Need for Change in Terminology:
- Critical Role of Transmission Mode in Preventive Measures: The mode of pathogen transmission dictates the most effective control measures for preventing their spread.
- Early Covid Response and Delay in Ending Wearing of Mask: In the early stages of the Covid outbreak in 2020, the WHO asserted that the rapidly spreading virus was not airborne.
- This delay in endorsing mask-wearing and indoor ventilation recommendations may have resulted in loss of life.
- Misguided Advice: The WHO issued guidance for health workers caring for Covid patients asserting that the virus spread primarily through direct contact and respiratory “droplets” measuring 5-10 micrometres in diameter.
- It recommended maintaining distancing more than 1 meter within which these droplets were thought to fall to the ground along with hand-washing, surface cleaning and sneezing into elbows.
- With personal protective equipment in short supply, people were advised not to wear masks unless they were sick or taking care of covid patients.
- This advice has since been proved to be misguided as the transmission can occur over far longer distances, and the broad usage of masks among populations helped stem its spread.
Significance of Change in Terminology:
- Unified Terminology: The terminology sets a common language for engineers, physicists, clinicians, and epidemiologists.
- They will be able to apply this to determine the broad implications of airborne particles and the effectiveness of countermeasures like face masks and respirators.
- Protective Measures for Short-Range Airborne Transmission: Short-range airborne transmission means healthcare workers will need respirator masks when interacting with certain patients.
Government Response to Airborne Diseases:
- Guidelines for Reducing Indoor Respiratory Particle Circulation: The US Centers for Disease Control and Prevention outlined actions people can take to reduce the amount of respiratory particles circulating indoors.
- Guidebook by WHO: An 83-page guide that can be used to evaluate the risk of airborne COVID-19 spread was released by the WHO itself in March.
- Mandating Indoor Air Quality Standards: Some researchers have proposed mandating indoor air quality standards for public buildings.
April 19, 2024